The invention relates to a tire monitoring system for a vehicle for establishing tire-specific parameters, having a valve stem, at least one fastening element, and a tire pressure sensor with a housing in which means are accommodated for determining at least one tire-specific parameter and for the wireless transmission of the at least one tire-specific parameter, preferably to a vehicle control device, wherein the housing has a mounting region and the valve stem comprises an attachment section, and wherein the attachment section of the valve stem and the mounting region of the housing are releasably connected to one another with the aid of the fastening element when the at least one fastening element is in a locking position.
The vehicle safety and reliability are central aspects of automobile engineering. Therefore, simply for reasons of safety, the tire pressure on vehicles, or motor vehicles, should be checked regularly, which is something that is frequently neglected by vehicle drivers. For this reason, detection devices in the form of tire air pressure sensors are increasingly used in modern vehicles, which sensors automatically measure tire air pressure and transmit this to a vehicle-side control device. As a result, defects or accidents that can be attributed to insufficient tire air pressure can be avoided. Therefore, by means of this automatic measurement of the tire air pressure, a critical deviation of the measured tire air pressure from a tire pressure target value should be detected early and indicated to the vehicle driver, such that a manual checking is no longer necessary. With systems of this type, for the automatic measurement of the tire air pressure, a tire air pressure sensor is disposed on each wheel, or tire, respectively. A tire air pressure sensor frequently comprises at least one sensor for determining the tire air pressure or the temperature thereby, as well as a transmission unit and, optionally, an evaluation unit, which, however may also be provided in the vehicle.
With a tire monitoring system known from DE 10 2010 050 365 A1, the system comprises a valve stem, a tire air pressure sensor and a fastening element that secures the valve stem to the tire air pressure sensor, wherein the fastening element is in the form of a screw. In order to mount the valve stem on the tire air pressure sensor, the attachment section of the valve stem is inserted in a receiver formed on the housing of the tire air pressure sensor. The receiver has a bore hole, running transverse to the insertion direction of the valve stem, and into which the fastening element, designed as a screw, is screwed in order to attach the valve stem to the housing. The disadvantage with this known tire pressure control system is that there is a risk in the assembly process that the fastening element, designed as a screw, may become lost, and that an assembly aid in the form of screwdriver is necessary for establishing the screw connection, which in the end, holds the valve stem on the housing of the tire air pressure sensor.
A tire monitoring system of the type described in the introduction is known from DE 10 2004 048 244 A1 for example. This known tire monitoring system likewise has a valve stem, a tire air pressure sensor and a fastening element that secures the valve stem on the tire air pressure sensor. With this tire pressure control system, the fastening element is designed, however, as a spring clip, wherein the valve stem is inserted in a receiver formed on the housing for the tire air pressure sensor for attaching the valve stem to the tire air pressure sensor. The receiver has an insertion slot, running transverse to the insertion direction of the valve stem, and in which the fastening element, designed as a spring clip, is inserted, in order to engage in a recess formed in the peripheral surface of the attachment section of the valve stem, and as a result, to attach the valve stem to the housing. The fastening element assumes a locking position thereby. With this known tire monitoring system, there is the disadvantage that the fastening element is provided as a separate component, which may become lost, either during transportation or during the assembly/disassembly. In particular, there is the danger with this known tire monitoring system that the fastening element may loosen during operation, and abandon the locking position, such that the tire air pressure sensor can become detached from the valve stem and become damaged.
The fundamental object of the invention is to provide a solution, by which means a tire monitoring system is provided in a constructively simple manner, which is light, compact, inexpensive, and easy to install.